A. 整体现浇钢筋混凝土 B. 采用的混凝土强度等级小于C20 C. 预制混凝土屋面板 D. 砌体
A. 1 B. 2 C. 3 D. 4
A. 3 B. 6 C. 9 D. 12
A. were B. have been C. was D. are
A. 开挖 B. 加固 C. 填筑 D. 压实